ABS has awarded three ships in the Hyundai Merchant Marine (HMM) fleet with what is believed to be the first class notation specific to parametric roll issued to industry. The optional class notation was issued against criteria contained in the ABS Guide For The Assessment Of Parametric Roll Resonance In The Design Of Container Carriers, which provides design and analysis measures to determine if a particular vessel is vulnerable to parametric roll and the potential magnitude of the roll motions. It was the first class criteria addressing the subject that is firmly based on ship motion analysis supported by extensive simulations.
The “PARR C1” notation has been granted to the 4700 TEU Hyundai Forward, and 8600 TEU vessels Hyundai Faith and Hyundai Force. Criteria in the Guide are based on some of the most advanced analysis done to date in the industry, through joint research by ABS and Hyundai Samho Heavy Industries. ABS has a long experience with container carriers and is involved with a number of next generation Ultra Large Containership (ULCS) design development projects with Korean shipyards.
According to ABS Engineer Dr. Vadim Belenky, a ship motions specialist and former academic who led the multi-year research project, by applying the criteria in the Guide, designers can determine if a ship may be vulnerable to parametric roll in worst case scenarios. “If the design is vulnerable,” explains Belenky “several options exist to address this vulnerability.” These include design modifications such as the inclusion of flume tanks and conducting numerical simulation studies and model testing to develop a series of diagrams that will define the combinations of speed and course, that given sea state and load conditions, might be dangerous. These diagrams can be placed on board the vessel to provide guidance to the Master and navigating officers.